1. Field of the Invention
The present invention relates to a protective mechanism for syringes, needles, or other devices having pointed or sharp objects. Specifically, it relates to a protective mechanism for such devices in the medical/pharmaceutical sector of use.
2. The Prior Art
Numerous injuries in the clinical or other medical sector are caused by accidental contact with sharp and/or pointed treatment devices, primarily syringe needles or scalpels. Such injuries are particularly hazardous for the persons affected because there is often an infection risk involved, for example in the case of direct penetration of bodily fluids of patients infected with hepatitis or the HI virus, for example, into the blood system of the injured person.
Therefore it is desirable to equip such medical devices with protective mechanisms, which offer protection from injury.
The following requirements exist for such protective mechanisms:                An accidental collision between point, needle and/or blade and user (injury caused by sticking or cutting) must be precluded.        The hands must always remain behind the point, needle and/or blade.        The protective mechanism should be an integral part of the device that has the point, needle and/or blade.        It should be effective both before and shortly after use of the device (an injection, for example), and during the disposal process (waste).        Protective mechanisms should be easy to use, without instructions, and in an ideal case should function automatically and be operated with one hand.        During use of the device (an injection, for example), in other words while the protection is necessarily deactivated, the protective mechanism is not allowed to be in the way of the user.        It should give clear visual indication of its status (protection in effect/not in effect).        Its activation should ideally be structured to be irreversible, so that the protection cannot be cancelled out.        The protective mechanism should be reliable and environmentally friendly, as well as inexpensive.        
A plurality of mechanisms is known for protection from sharp needles, which mechanisms are a more or less ideal implementation of the above demands. For example, U.S. Pat. No. 4,735,618 and U.S. Pat. No. 6,796,968 disclose needle sheaths that are pushed over the needle after an injection has been administered, using hinge joint mechanisms. U.S. Pat. No. 5,879,337 describes a needle cap that is pushed along the needle, sliding to the point, and held using a holder thread, in such a manner that it does not slip off the needle point. Spring elements are described here, as well.
The protective mechanisms are usually simple mechanical systems composed of plastic injection-molded parts and, if necessary, spring elements, which are not a hindrance during the injection, but can be activated with simple triggering principles after the injection, and from then on surround sharp needles in protective manner.
The protective devices can already be integrated into syringes or cannulas, or can be additional parts that can subsequently be attached to cannulas or syringes.
Aside from devices that can simply be pushed, flipped, or clamped by hand, more convenient syringe protectors are also known, which are automatically triggered at the end of an injection (syringe piston in the end position) and bring the cannulas into a secured position or bring a protective tube into a barrier position.
The major disadvantage of the known syringe protectors is their mechanical complexity and material properties, which result in significant additional costs for the syringe body.
Another disadvantage of the known syringe protectors is that these must usually be connected with the syringe or cannula subsequently, in other words they require an additional production step.